Process for stabilizing bulked yarns and product thereof



Sept. 13, 1966 D. WILLIAMS. JR 3,271,943

PROCESS FOR STABILIZING BULKED mans AND PRODUCT THEREOF Filed Dec. 30,1963 4 Sheets-Sheet 1 iVV+++ INVENTOR EBENEZER DAVID WILLIAMS, JR

ATTORNEY p 1966 E. D. WILLIAMS, JR 3,271,943

PROCESS FOR STABILIZING BULKED YARNS AND PRODUCT THEREOF Filed Dec. 30,1963 4 Sheets-Sheet 2 FIG.4

auca-| ELOIIGATION. In AT .027 gpd. LOADING N U I RELATIVE HUIIIDITY; I.

IOISTIIRE C(IIITEIIT 0F YARN II INVENTOR EBENEZER DAVID WILLIAMS, JR.

BY 4m ATTORNEY p 1966 E. o. WILLIAMS, JR 3,271,943

PROCESS FOR STABILIZING BULKED YARNS AND PRODUCT THEREOF Filed D60. 30,1963 4 Sheets-Sheet 5 FIG.6

YARN IODULUS. 90d. m u 4:- 0v 0: w

RELATIVE HUMIDITY,

FIG.7

I 50 80 RELATIVE HUMIDITY, In

INVENTOR EBENEZER DAVID WILLIAMS,JR

BY J 3 ATTORNEY Sept. 13, 1966 E. o. WILLIAMS, JR 3, 3

PROCESS FOR STABILIZING BULKED YARNS AND PRODUCT THEREOF Filed Dec. 30.1963 4 sheets-sheet 4 L.-- it FRICTION INDEX T T AT 85 'l- RELATIVEHUMIDITY I I I I I I 0.1 0.2 0.3 0.4 0.5 0.6 0.? 0.8 0.9 L0

FIIIISII 0N YARN, I.

FIG.9

INVENTOR ATTORNEY EBENEZER DAVID WILLIAMS. JR.

United States Patent 3,271,943 PROCESS FOR STABlLlZlNG BULKED YARNS ANDPRODUCT THEREOF Ebenezer David Williams, Jr., Seaford, DcL, assignor toI. du Pont de Ncmours and Company, Wilmington, Dcl., a corporation ofDelaware Filed Dec. 30, 1963, Ser. No. 334,435 8 Claims. (Cl. 57-.140)

This invention relates to a method for treating a bundle of filamentssuch as a yarn or thread and to the products so obtained. Moreparticularly, the invention relates to bulky yarns composed ofindividually crimped filaments and a treatment of such yarns to improvetheir physical characteristics.

Artificial fibers are normally produced most easily in the form of yarnscomposed of continuous filaments. These continuous-filament yarns arevery strong because of the absence of loose ends that are unable totransmit imposed stresses. Their extreme uniformity and lack ofdiscontinuity, however, make conventional continuousfilament yarns muchmore dense than yarns made from staple fibers. On the other hand theproduction of yarns from staple fibers is time-consuming and requires acomplex series of operations to crimp the fibers, align the fibers intoan elongated bundle and then draw the bundle to successively smallerdiameters. Nevertheless the final spinning operation, which involves ahigh degree of twist, finally binds these discontinuous fibers togetherin the form of a coherent yarn having a considerably increased bulk. Theoccluded air spaces give them a lightness, covering power, andwarmth-giving bulk not normally poss ble with continuous-filament yarns.Thus, to get staple fibers that can be processed on conventional woolorcotton-spinning equipment, it has been the practice to cutcontinuous-filament yarn such as rayon, acetate, nylon, as well as thepolyacrylic and polyester fibers into short lengths for spinning intostaple yarn.

Developments in the textile industry have provided useful routes forimproving the bullk and covering power and recoverable elongation ofcontinuous-filament yarns without resorting to the staple-spinningsystems of the prior art. A well-known process for making stretchyarninvolves the steps of twisting, heat-setting and then bucktwisting to alow final twist level; Another yarn of improved bulk is preparedcommercially by the steps of twisting, heat-setting and backtwistingon-the-run using a false-twisting apparatus. This end product can hefurther modified by hot relaxing to improved the bulk and handle.stutter-box technique wherein the yarn is steamed to heatset it while itis in a compressed state in the stulfer box. Thus by passing a runningyarn into the nip of intermeshing gears, a crimpy yarn is obtained.Still another bulky yarn is produced by running a continuous-filament Iyarn over a heated blade. More recently methods have been developed inwhich crimp is imparted to continuousfilament yarns by subjecting themto the action of a turbulent tluid stream while in a plasticizedcondition and thereafter setting the filaments in the crimpedconfiguration.

The described prior art yarns are not only bulky in a relaxed conditionbut are also quite extensible when subjected to light loads. Although ahigh degree of extensibility is of considerable benefit in themanufacture of so-called stretch fabrics, a low degree of extensibilityis desired for other textile articles such as firm fiat-woven fabrics,heavy warp-knit structures and tufted carpets. In the latter instance,the very highly bulked yarns are not only difiieult to process intofinished articles, but also the finished goods may frequently bedeficient in terms of quality and uniformity. It has heretofore beenrecognized that the performance of these highly crimped Bulk yarn isalso prepared by the well-known 3,?7l,$l lli Patented Sept. 13, 1966yarns for such purposes could be markedly improved if the stretchproperties were modified so that the extensibility is reduced Whilemaintaining the voluminous nature. A known method of accomplishing thisis to extend the crimped yarns and pass them through a heated zone whileunder an accurately controlled degree of relaxation, and set the yarn inthe desired condition. While normally satisfactory, such thermaltechniques suffer from the disadvantage that they require expensiveheating devices in addition to complicated temperature regulatingdevices.

Another deficiency in the prior art yarns relates to the wide variationscommonly experienced in frictional characteristics. These tend to givevariations in the feeding of the bulked yarn through the guides andneedles of carpet-tutting machinery, for example, and also to detractfrom the uniformity of the finished carpeting.

A principal object of this invention, therefore, is to provide animproved bulky yarn which retains a selfcriruping tendency and possessesa desirable combination of bulk, stretch and frictional characteristics.Another object is to provide a novel method of producing such improvedbulky yarns. An additional object is a method for treating a bulky yarnto regulate its crimping tendencies over a wide range of commercialprocessing conditions. Another object is to provide a method forproducing a bulky yarn with a relatively low self-crimping 1 tendencyand low frictional characteristics while substantially retaining thebulkiness of the yarn. The invention also provides a simple andhighlyieflicient method for regulating the bulk and stretch propertiesof a bulky yarn.

In accordance with the present invention a method is provided forreducing the extensibility of a bulky yarn composed of crimpcdcontinuous filaments of a synthetic polymer. The method comprisesapplying liquid water to a running length of the yarn at normaltemperatures while the yarn is under a tension of at least 0.02 gram perdenier and winding the water-treated yarn under tension into a package,the quantity of water applied to the yarn being at least of theequilibrium content of the filaments at relative humidity as measured at20 C. In preferred embodiments of the invention the bulky yarn has afriction index less than about 3.0, and the polymer is a polyamide,especially poly(hcxamethylene adipamidc). The yarn treatment isadvantagcously carried out as a continuous method which includcs thesteps of spinning the filaments, collecting the filaments in the form ofa multifilameut yari, bulking and relaxing the filaments of the yarn,subsequently effeeling the water/tcnsioning treatment and winding thebulky yarn under tension into a package. For purposes of this invention,the yarn is preferably bulked by [coding continuously through aplasticiziug: lluid stream to yield a highly crimpcd yurnwhich is thencooled and set while in a relaxed condition.

The resultant yarn product has a relatively low crimping tendency, lowextensibility and low frictional characteristics which favor theperformance of the yarn over the wide range of humiditics encountered incommercial processing.

The invention, its advantages and the manner of conducting it will bemore clearly understood by referring to the drawings and disclosurewhich follow.

FIGURE 1 is a longitudinal view of a bulky continuous multi-filamentyarn produced by the invention.

FIGURE 2 is a diagrammatic perspective view of apparatus suitable fortreating a bulked yarn in accordance with the present invention.

FIGURE 3 is a schematic perspective view of apparatus for combining theprocess of this invention with steps of mclt spinning, drawing, bulkingand relaxing to provide an integrated continuous manufacturing processfor obtaining improved bulky continuous filament yarns.

FIGURE 4 shows graphically the percentage elongation of the product ofthe invention when subjected to low tensile loading under varioushumidity conditions.

FIGURE 5 shows graphically the relationship between the elongation ofthe product of the invention under low tensile loading and the moisturecontent attained during its processing.

FIGURE 6 shows graphically the relationship between the ini ial tensilemodulus of the product of the invention and the relative humidity of theambient air.

FIGURE 7 shows graphically the effect of relative humidity onretraction, a measure of crimping tendency.

FIGURE 8 shows graphically the relationship between the frictionalcharacteristics of the product of this invention and its finish content.

FIGURE 9 is a schematic diagram of an apparatus for measuring frictionalcharacteristics.

, Referring now to the drawings, FIGURE 1 illustrates the bulky yarn ofthis invention. It shows a yarn bundle composed of a plurality ofindividual continuous filameats, each of which has a wavythree-dimensional crimp. The configuration of the individual filamentsprevents them from packing into a'closely nested arrangement in the yarnbundle, even when under considerable tension. This property isparticularly useful in increasing the bulk and cover of tightly woven,knit or tuftedpile textile articles. The tendency of the crimpedfilaments to intermingle or interentangle lends a slight coherence tothe yarn bundle which may be increased by known pneumatic interlacing ormechanical twisting processes. 7

in its preferred embodiment, the yarn is composed of synthetic organicfilaments which have'been initially crimped by a plasticizingfluid-stream of compressible fluid as in British Patent 905,895 or byconveying a yarn in a fluid stream against a surface to mechanicallydeform it while in a plastic condition as in British Patent 861,108. Theinvention may also be applied to certain yarns which have been treatedin the known stutter-box, in the falsetwist heat-setting process orother modes of crimping. As will be seen in the subsequent description,the preferred crimped product is a bulky nylon continuous filament yarnwhich is packaged under at least 0.02 g.p.d. tension with at least 4% byweight moisture and with a friction index less than 3.0. The crimpingtendency and other physical characteristics of the yarn are maintainedat desired levels so as to render the yarn particularly us ful forfabrication into textile products.

FIGURE 2 illustrates schematically the process of this invention using asimple form of apparatus. A bulky feed yarn 20 containing apredetermined quantity of a lubricating finish is advanced at a desiredspeed by passage between feed rolls 21 and 22 and passes through a sprayof liquid water 23 emitting from atomizing nozzle 24 while undertension, whereupon the treated yarn 25 is wound into a package 26.Package 26 is wound on rotatable cylindrical core 27 with a suitabletraverse, not shown, and is surface-driven by rotating cylindricaldriveroll-28. The relative speeds of the drive roll 28 and feed rolls 21and 22 are adjusted to attain the required tension in the treated'yarn25. Alternatively the tension on the treated yarn may be adjusted by thewinding torque of package 26.

FIGURE 3 illustrates a process for producing meltspun bulked yarns bythe invention. Filaments 30 from spinneret 31, quenched by a cross-flowof cooling air from plenum 32, are converged at guide 33 and passedaround a pair of rolls 34. The yarn passes around draw pin 35 and iscontinuously drawn by Wraps around a pair of rolls 36' moving at higherspeed. The drawn yarn then passes over idler roll 37 and into fluid jet38 in which the yarn is plasticized and treated by a stream ofcompressible fluid. The bulked yarn leaving the jet is crimp-set onrevolving screen-surfaced drum 39 and, while riding on the drum andunder no applied tension, is subjected to a spray of lubricating finish40 issuing from spray nozzle 41. The bulked yarn is then taken fromthrough guide 46 to a package 47 under the required tension. The packageis wound on cylindrical core 48 and surface-driven by drive roll 49. 1

After the moisture treated bulky yarn has been wound 7 under tension,the moisture surrounding the filaments may gradually become dissipatedinto the atmosphere during shipment and handling of the package orduring use of the yarn; Notwithstanding such changes in mois turccontent, however, the improved properties which characterize theproducts of the invention, including relative insensitivity to humidityand humidity fluctuations, continue to persist.

To provide a bulky extensible yarn which is relatively insensitive tovariations in relative humidity during textile processing, the moisturecontent of the treated yarn as it is Wrapped under tension must be atleast 50% of the equilibrium moisture content of the fibers at relativehumidity (at 20 C.). In the case of 66 nylon this is approximately 4weight percent. For most purposes the yarn in the package should containno more than about 10% by weight of water. If allowed to'appreciablyexceed this amount, water droplets will be thrown from the moving yarnonto the process machinery and furthermore, the wound packages of yarnwill be unduly Wet and soggy. i

In accordance with the method of the invention, the water treatment of arunning length of bulky yarn under tension is conducted at normaltemperatures. It is a sig nificant feature of the invention that themethod can be satisfactorily conducted at atmospheric or ambienttemperature conditions. Depending upon the geographical location, themanufacturing plant facilities, and other factors, the method willnormally be performed at temperatures of 5 to 40 C., most frequently at15 C. to 35 C. Similarly it is unnecessary to heat or cool the waterwhich is 'used in treating the yarns, the aforementioned temperatureranges also being satisfactory for this purpose.

No special precautions need be observed with respect to the purity ofwater used for the yarn treatment so long as it is free of materialswhich would damage the filaments. The water need not be distilled ordemineralized. Frequently it may be desirable to include thereinfinishing agents, antistatic agents or other materials to modify theproperties of the yarn. Any of several readily available devices may beused for the application of moisture, such as spray, grooved applicator,felt, dip tank or other means best suited to the circumstances. The yarnspeed in the process is limited only by the mechanical limitations ofthe applicator and therefore the yarn treatment is suited to couplingwith other yarn treatments, as illustrated above.

According to the process of the invention, the axial tension on the yarnduring winding of the package must be at least 0.02 gram per denier(0.18 g.p. Tex). tension of 0.15 g.p.d. (1.35 g.p. Tex) has been foundpreferable, yielding yarn exhibiting a suitable extensibility withoutincurring mechanical problems in the winding of the package. Highertensions are permissible to further reduce the extensibility of the yarnso long as the elastic limit of the filaments is not exceeded.

The utility of the product is further enhanced by the application of alubricating finish to provide a friction index which is less than about3.0 as measured by the technique described hereinafter. A lubricantbased on mineral oil is satisfactory for this purpose although otherliquids which provide a lubricating film may be used.

The amount of finish usually required for 66 nylon yarn is approximately0.7 weight percent on the yarn, although the quantity applied may rangefrom 0.4% to 1.0%, so long as it is applied uniformly. As in the case ofmoisture application, excessive amounts of finish lead to undesirabledeposits on the processing machinery and to messy unmanageable yarnpackages. Any of the suitable devices of the prior art may he used forapplying the finish. Preferably the finish is applied to the yarn beforethe moistening-tensio'ning step. However, the finish may be appliedduring the tensioning step, e.g. simultaneously with the water by usingan aqueous emulsion of the lubricant.

The effect of the process of this invention on the I properties of thebulked yarns and their usefulness is illustrated in their performance inthe manufacture of tufted carpets. An important aspect of patternformation in dyed carpets is control of tuft height so that high loopsand low loops can be formed according to a prescribed pattern, withsharp transition from one height to another. A yarn which is highlyextensible and presents frictional drag in the tufting needles isdetrimental to the tuiting operation. This difficulty appears to bemagnified when the tufting is performed at a time when the relativehuidity of the surrounding atmosphere is at a high level. The process ofthis invention permits uniform regulation of the extensibility of thevery bulky yarn over a wide range of humidity conditions. The resultshave been judged both by laboratory testing methods and by subjectiveobservation of carpet quality.

One measure of extensibility of the bulky yarn is determincd by theelongation of a yarn bundle when sub-' jected to a low tensile load,arbitrarily selected at 0.027 gram per denier (a. 100 gm. load for3700-denier yarn).

' The resistance to stretching is indicated by the modulus,

the slope of the first part of the stress-strain curve for the bulkedyarn. The selfcrimping tendency, or the retraction of yarn at zerotension, is observed by measuring the percent decrease in length of alength of yarn upon hanging freely for minutes after release of atension load. The crimp force is the force exerted by a given length ofyarn on the fixed clamps of a tensile testing device after 10 minuteselapsed time. The relationship of the properties measured by thesemethods to the quality of the carpet produced from the yarns will beshown in the examples.

EXAMPLES 1-5 Bullred nylon continuous-filament yarns were prepared attake-up speeds in excess of 500 y.p.m. The water and atmosphere wereboth at essentially room temperature, e.g. 25 C. The physical propertiesof the treated yarns are shown in Table I.

The tensile properties, tenacity and elongation, of the treated yarnswere essentially identical. and unaffected by the differences inmoisture and tension. The filaments were highly crimped as indicated bythe crimp frequency. When boiled-off, a laboratory immersion in boilingwater similar to the scouring and dyeing conditions of corn- 'mcricalprocessing, the crimp elongation, described in British 905,895, wassubstantial. The latter indicates that the treated yarns retain a highdegree of bulkiness even after forming into a finished textile article.When the yarns of the various examples were formed into carpets, theyarn of Example 5 proved to be superior in terms of tuft-formation andclarity of the pattern in the carpet. Thus it appears that theperformance of the bulked yarn in carpet fabrication is related to thecrimping characteristics. This is exemplified by the fact that incomparison with the yarns of Examples 1 through 4, the yarn of Example 5has a low elongation under low loading, a low self-crimping tendency(retraction and crimping force) and a relatively high modulus, all theseproperties being measured at high relative humidity. Example 1demonstrates that this improvement is not accomplished by merely windingunder tension.

As shown in FIGURE 4, yarns treated according to the process of theinvention are less susceptible to variations, in relative humidity ofthe surrounding atmosphere. The elongation at low load, orextensibility, of the yarn of Example 5 changes little over the range ofto 85% relative humidity, as evidenced by the lower line of FIG- URE 4.Similarly, the change in elongation of the yarn of Example 3, alsotreated at 550 gm. tension, is relatively small over the range ofrelative humiditics. The yarns of Examples 2 and 4, treated under verylight tension, are affected to a greater extent by humidity.

The effect of applying liquid moisture is also apparent from FIGURE 4.The yarns of Examples 4 and 5, containing approximately 6% moisturecontent, have a s'gnificantly lower tendency to stretch than the yarnsof Examples 2 and 3. The differences among the yarns are less evident atlow humidities. It is indeed surprising to find that the sensitivity ofa highly oriented hydrophobic yarn to changes in atmospheric humiditywould be diminished by the application of iiquld water at roomtemperature while the yarn is under tension.

Table 1 NYLON YARN Example Yarn tension:

At moisture appln., g.p.d. 0 013-. 02 15 013-. 02 15 At winding, g.p.d.12 (Jl3. 02 .15 013-. 02 .15 Yarn moisture. percent by wt" 1. (H. 5 3 66 Yarn finish content, percent by wt 0. 1 0. 7a 0.75 0.75 0. 75Tenacity, g.p. 3. 4 3. 4 3. 4 3. 5 Elongation at; break, percent 53 5O49 Crimps er inch after boil-oif 18 20 20 16 Crimp e ongation alterboil-0t], percent 83 83 77 67 Stressstrain properties at 85% relativehumidity:

Yarn elongation at .027 g.p.d. loading,

percent 7. 5 7. 5 5. 5 5. 3 3. 6 Initial modulus, g p.d 2. 1 1. 1 2. 22. 5 3. 6 Retraetion, percent 8. .3 8. 0 7.0 4. 0 4. O Crimping force,g.p.d 2. 1 2. 1 3. 7 2. 1 1. 4

by the method and apparatus illustrated in FIGURE 3. Nylon 3700-denieryarns with 204 filaments of trilobal cross-section were crimped in aplasticizing stream of heated air under identical conditions. The bulkedyarns were moistened with various amounts of water while The effect ofmoisture applied under tension, for the yarns of Examples 2 through 5,is illustrated more clearly in FIGURE 5. The high-humidity low-loadelongation (or humid-extensibility), decreases as both yarn moisturecontent and treatment tension increase. Based on the apunder varioustensions and then wound up intoapackage pearance of tufted carpets, itappears that superior re- 'ditions in commercial use.

available magnetic, electrical or mechanical types. yarn is continuouslypulled through the eye of a tufting 7 sults are achieved when the yarnextensibility is less than The data of FIGURES indicate that in the caseof 66 nylon the treatment tension should exceed .02 g.p.d.

illustrated in FIGURE 6. The data were obtained from a series of yarnstreated as in Examples 1-5. Yarns 8 index and the finish content of theyarns of Examples 6 to is apparent from FIGURE -8. The friction indexdecreased to a low and uniform level when the finish content of the yarnexceeded 0.4%. Carpets made from yarns with a friction index less than3.0 were superior with respect to definition of tufts and pattern tothose produced from yarns with lesser amounts of finish. Hence,adjustment of the yarn finish content to obtain a suitably low frictionindex provides a further improve- :tre'ated under higher'tension and athigher moisture con- 10 ment in the product and process of thisinvention.

Table II RELATIONSHIP BETWEEN FRICTIONAL CHARACTERISTICS AN D FINISHCONTENT OF YARN Example Finish content, wgt. percent 0. 1 0.2 0.51 O. 66O. 93 Moisture Content, wgt. percent 4. 8 6. 0 6. 1 6. 3 6. 3 Denier 3,730 3, 790 3, 770 3, 770 3, 780 Tenacity, g.p.d 3. 3. 5 3. 6 3. 4 3. 6Elongation, percent. at brcak 47 48 48 51 49 Crimps per inch afterboil-o 13 14 13 i4 14 Crimp Elongation after boil-off percent. 66 64 6766 64 Friction Index, Tz/T 4. 05 3. 00 2. 73 2. G4 2.70

tent have a higher initial modulus and are less affected by humidity. Ahigher modulus is indicative of a lower yarns under tension with waterare most pronounced when the yarn possesses a low and uniform frictionindex. If the frictional characteristics of the yarn are nonuniform, anextensible yarn is likely to be stretched to different degrees as theindividual tufts are formed in carpet fabrication. It follows thatproper use of a lubricant can readily contribute to the uniformity oftuft-formation. A test of yarn frictional characteristics has beendevised to evaluate the effect of finish. In this test the bulked yarnis drawn through the eye of .a tufter needle at controlled speeds androom humidities simulating actual tufting con- Yarn tension is measured,dynamically, upstream and downstream from the needle. The ratio ofoutgoing tension, T to ingoing tension, T at. constant T is taken as thefriction index.

The apparatus and method for determination of the friction index isillustrated in FIGURE.9. The bulky yam to be tested is withdrawn frompackage 26 regulated at a constant value, approximately .008 g.p.d., bytension regulator 61, which may be any of the readily The needle 63 sothat the shank of the needle bisects a 25 included angle between theingoing and outgoing threadline. The take-off speed of the yarn ismaintained at 45 y.p.m. by suitable means such as take-off roll 65 andseparator roll 66. Ingoing tension, T is measured by V tensometer 62 andoutgoing tension, T is measured by tensometer 64. Data measured by thistechnique are reported in Table II and are discussed below.

EXAMPLES 6-10 oil lubricating finish. The relationship between frictionThe practice of this invention may be utilized with numerous knownsynthetic fiber-forming materials. These include such organic materialsas polyamides, e.g., poly(caproamide) and poly(hexamethylene adipamide);polyesters, e.g., terephthala-te esters of ethylene glycol and atrans-p'hexahydroxylylene glycol; polyalkylenes, e.g., polyethylene andpolypropylene; .polyvinyls and polyacrylics, e.g., polyacrylonitrile, aswell as copolymers.

The yarns are not restricted to filaments of anyparticular'cross-section. The trilobal filaments of the above examplesare preferred vfor many textile articles. ments of round, cruciform,delta-shaped, ribbon, dumbbell and other non-circular cross-sections canbe processed as well. The filaments may also be of various sizes asmeasured by denier per filament. Further, a mixture of filament deniersand cross-sections may be used in this invention.

While the product of this invention has been shown to be particularlyuseful for the manufacture of tufted carpets, it retains the propertiesand attributes of the bulky yarns which are fed to this process andwhich are useful for other textile articles such as woven and knitgoods.

What is claimed is:

1. Method for reducing the extensibility of a bulky yarn composed ofcrimped continuous filaments of a polyamide, said method comprisingapplying liquid water to a running length of the yarn at normaltemperatures while the yarn is under a tension of at least 0.02 gram perdenier and winding the water-treated yarn under tension into a package,the quantity of water applied to the yarn being at least 50% of theequilibrium content of the filaments at relative humidity as measured at20 C.

2. Method of claim 1 wherein the said bulky yarn has a friction indexless than about 3.0.

3. Method for reducing the extensibility of a bulky yarn composed ofcrirnped continuous filaments of poly- (hexamethylene adipamide), saidmethod comprising applying liquid water to a running length of the yarnat normal temperatures while the yarn is under a tension of at least0.02 gram per denier and Winding the watertreated yarn under tensioninto a package, the quantity of water applied to the yarn beingsufiicient to provide a yarn water content of at least 4% by weight.

4. Method of claim 3 wherein the said bulky yarn has a friction indexless than about 3.0.

5. Method of claim 3 wherein the said yarn water content is 4 to 10% byweight.

6. In a method for producing a bulky yarn composed of continuousfilaments of a polyalnide, which method includes the steps of spinningsaid filaments, collecting said filaments in the form of a yarn, bulkingand relaxing the filaments of the yarn, and subsequently winding thebulky yarn under tension into a package; the improvement wherein thewinding of the bulky yarn into said package includes the step ofapplying liquid water to a r nning length of the yarn at normaltemperatures while the yarn is under a tension of at least 0.02 gram perdenier, the quantity of water applied to the yarn being at least 50% ofthe equilibrium content of the filaments at 100% relative humidity asmeasured at 20 C.

7. In a method for producing a bulky yarn composed of continuousfilaments of poly(hexame'thylene adipamide) which method includes thesteps of spinning said filaments, collecting said filaments in the formof a yarn, bulking and relaxing the filaments of the yarn, andsubsequently winding the bulky yarn under tension into a package; theimprovement wherein the winding of the bulky yarn into said packageincludes the step of applying liquid water to the yarn at normaltemperatures While the yarn is under a tension of at least 0.02 gram perdenier, the quantity of water applied to the yarn being sutlicient toprovide at least 4% water based on the weight of the yarn. V

8. A bulky yarn produced by the method of claim 1..

References Cited by the Examiner UNITED STATES PATENTS 2,364,467 12/1944Nickerson 2859.5 2,837,809 6/1958 Muller 28-76 2,960,752 11/1960 Sonnino28-76 3,145,133 8/1964 Barton.

ALEXANDER H. BRODMERKEL, Primary Examiner. A. L. LEAVITI, AssistantExaminer.

1. METHOD FOR REDUCING THE EXTENSIBILITY OF A BULKY YARN COMPOSED OFCRIMPED CONTINUOUS FILAMENTS OF A POLYAMIDE, SAID METHOD COMPRISINGAPPLYING LIQUID WATER TO A RUNNING LENGTH OF THE YARN OF NORMALTEMPERATURES WHILE THE YARN IS UNDER A TENSION OF AT LEAST 0.02 GRAM PERDENIER AND WINDING THE WATER-TREATED YARN UNDER TENSION INTO A PACKAGE,THE QUANTITY OF WATER APPLIED TO THE YARN BEING AT LEAST 50% OF THEEQUILIBRIUM CONTENT OF THE FILAMENTS AT 100% RELATIVE HUMIDITY ASMEASURED AT 20*C.